A sending method and a receiving method for multi-terminal media synchronization under a heterogeneous network, and a sending device and a receiving device

Abstract

The present application relates to the technical field of multimedia content, and especially relates to a transmission method for multi-terminal media synchronization under a heterogeneous network.The present application provides a sending method for multi-terminal media synchronization under a heterogeneous network: all general encapsulation units and media time indication information are encapsulated to obtain media encapsulation data, wherein the media time indication information contains a presentation time corresponding to each general encapsulation unit; a buffer synchronization algorithm is designed to obtain media synchronization data from the media packaging data through the buffer synchronization algorithm; wherein the buffer synchronization algorithm refers to adjusting different transmission channels so that the time when the media packaging data finally reaches the terminal is consistent with the preset time.The present application provides a transceiving method and device for multi-terminal media synchronization under a heterogeneous network, which can ensure that users have consistent experience at the same time on each terminal.

Description

Technical Field

[0001] This invention relates to the field of multimedia content technology, and in particular to a method for transmitting media synchronously across multiple terminals in a heterogeneous network. Background Technology

[0002] With the rapid development of internet technology and multimedia applications, users' demands for consistent and high-quality cross-terminal media experiences are increasing. In multi-terminal usage scenarios, such as remote conferencing, online education, and cloud gaming, users often need to receive and play multimedia content through different types of terminal devices (such as smartphones, tablets, and smart TVs). A typical application scenario is that media content shot simultaneously from multiple cameras is transmitted through heterogeneous networks and then presented synchronously on multiple terminals. For example, in a concert setting, users can watch the main viewpoint video on a large screen (TV) and the viewpoint they are interested in on a small screen (phone or tablet). Regardless of whether they are watching on a large or small screen, users see and hear the performance synchronously at the same time, and have a consistent experience on each terminal at the same moment. However, the existence of heterogeneous network environments, such as the hybrid connection of wireless networks (Wi-Fi, 5G, LTE) and wired networks, brings complex factors such as network latency, bandwidth jitter, and packet loss rate, which pose a serious challenge to the stability and reliability of multi-terminal media synchronous transmission.

[0003] Synchronous transmission of media across multiple terminals requires ensuring consistency in time and quality of playback content across terminals to avoid playback offsets or desynchronization due to network differences or varying terminal performance. Currently, mainstream synchronization methods are typically based on timestamp alignment, flow control protocols, or end-to-end transmission mechanisms. However, their performance is often limited when facing heterogeneous network conditions. For example, traditional timestamp alignment methods struggle to adapt to dynamic network environments, while end-to-end mechanisms struggle to balance real-time performance and synchronization when handling multi-network transmission across terminals. In recent years, next-generation media transport protocols (Smart Media Transport, SMT; MPEG Media Transport, MMT) have made rapid progress in technological evolution and innovation, attracting widespread attention from academia and industry. Current SMT / MMT protocols define presentation signaling related to synchronization, but do not explicitly design specific multi-terminal synchronization schemes for heterogeneous networks.

[0004] Therefore, in order to solve the key technical problems of synchronous media transmission across multiple terminals in heterogeneous network environments, there is an urgent need for a new transmission method that comprehensively considers network latency, packet loss rate, and differences in terminal performance, so as to ensure the consistency, real-time performance, and high quality of media playback across multiple terminals and improve the overall media experience for users in multi-terminal environments. Summary of the Invention

[0005] To address the problem of synchronous media transmission across multiple terminals in heterogeneous networks, this invention provides a method for transmitting, a method for receiving, a transmitting device, and a receiving device for synchronous media transmission across multiple terminals in heterogeneous networks.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows:

[0007] A method for transmitting media synchronously across multiple terminals in a heterogeneous network, the method comprising:

[0008] All general encapsulation units and media timing indication information are encapsulated to obtain media encapsulation data, wherein the media timing indication information includes the presentation time corresponding to each general encapsulation unit;

[0009] The media encapsulation data is packaged to obtain media packaged data;

[0010] A cache synchronization algorithm is designed to obtain synchronized media data from the packaged media data. Specifically, the cache synchronization algorithm adjusts the data for different transmission channels to ensure that the final arrival time of the packaged media data at the terminal matches a preset time.

[0011] The media synchronization data is sent to each terminal through various transmission channels.

[0012] Preferably, the media time indication information includes at least one of the following signaling structures:

[0013] Signaling structures used to indicate resource identifier types for media resources; and / or

[0014] A signaling structure used to indicate the length of the resource identifier for a media resource; and / or

[0015] Signaling structures used to indicate media resource sequence numbers; and / or

[0016] A signaling structure used to indicate the timing of media resource presentation.

[0017] A method for receiving audio and video synchronization across multiple terminals in a heterogeneous network, the method comprising:

[0018] Receive media synchronization data, which includes a general encapsulation unit for synchronization and media timing indication information;

[0019] The media synchronization data is parsed to obtain each general encapsulation unit and the corresponding media time indication information;

[0020] Design a cache adjustment algorithm, which refers to using the master clock based on the absolute rendering time to guide the synchronous rendering of each general-purpose packaging unit, ensuring that the final rendering is consistent with the master clock;

[0021] Based on the media time indication information, the data of each general encapsulation unit is adjusted according to the designed cache adjustment algorithm to obtain media cache adjustment data;

[0022] The media cache adjustment data is then rendered and presented.

[0023] Preferably, the media time indication information includes at least one of the following signaling structures:

[0024] Signaling structures used to indicate resource identifier types for media resources; and / or

[0025] A signaling structure used to indicate the length of the resource identifier for a media resource; and / or

[0026] Signaling structures used to indicate media resource sequence numbers; and / or

[0027] A signaling structure used to indicate the timing of media resource presentation.

[0028] The present invention provides a transmission apparatus for multi-terminal media synchronization in a heterogeneous network, comprising:

[0029] The encapsulation module is used to encapsulate all general-purpose encapsulation units and media timing indication information;

[0030] The packaging module is used to package the media encapsulation data;

[0031] The cache synchronization module is used to cache and synchronize the media packaged data.

[0032] The transmission module sends the obtained media synchronization data to each terminal through various transmission channels.

[0033] According to the present invention, a receiving device for multi-terminal media synchronization in a heterogeneous network is provided, comprising:

[0034] The receiving module is used to receive media synchronization data;

[0035] The parsing module is used to parse the media synchronization data to obtain each general encapsulation unit and the corresponding media time indication information;

[0036] The cache adjustment module designs a cache adjustment algorithm to adjust the data of each general encapsulation unit to obtain media cache adjustment data;

[0037] The rendering module renders and presents the media cache adjustment data.

[0038] The beneficial effects of this invention are as follows: This invention is based on a new generation of media transmission protocol to realize the service of multi-terminal media synchronization under heterogeneous network, and uses media time indication information to realize the synchronous interaction of media consumption information. Attached Figure Description

[0039] Figure 1 The diagram shown is a flowchart of a sending method according to an embodiment of the present invention;

[0040] Figure 2 The diagram shown is a flowchart of a receiving method according to an embodiment of the present invention;

[0041] Figure 3 The diagram shown is an overall flowchart of the synchronization method of the present invention;

[0042] Figure 4 The diagram shown is a schematic diagram of the transmitting device structure according to an embodiment of the present invention;

[0043] Figure 5 The diagram shown is a schematic diagram of a receiving device according to an embodiment of the present invention. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0045] To gain a deeper understanding of the technical solution of this invention, relevant technical terms will first be explained. A media resource (Asset) refers to any multimedia data used to establish multimedia presentation; it is a logical collection of content fragments that encapsulate encoded media data and have the same media resource identifier. Content fragments are named Common Encapsulation Units (CEUs), and the encoded media data they contain can be temporal or non-temporal. Temporal data refers to encoded media data with an inherent timeline, requiring data units to be decoded and presented synchronously at a specified time, such as audio and video content. Conversely, non-temporal data refers to data types that do not have an inherent timeline when decoding and presenting media content, such as text and image information. Furthermore, within the same media resource, CEUs containing temporal data cannot overlap in presentation time.

[0046] Current SMT / MMT protocols define presentation signaling related to synchronization, but do not explicitly design specific multi-terminal synchronization schemes. Therefore, to solve this problem, this invention proposes a sending and receiving method for multi-terminal media synchronization in heterogeneous networks, ensuring that users have a consistent experience on all terminals at the same time.

[0047] like Figure 1 As shown, this invention proposes a method for transmitting media synchronization across multiple terminals in heterogeneous networks. The method includes:

[0048] All general encapsulation units and media timing indication information are encapsulated to obtain media encapsulation data, wherein the media timing indication information includes the presentation time corresponding to each general encapsulation unit;

[0049] The media encapsulation data is packaged to obtain media packaged data;

[0050] A cache synchronization algorithm is designed to obtain synchronized media data from the packaged media data. Specifically, the cache synchronization algorithm adjusts the data for different transmission channels to ensure that the final arrival time of the packaged media data at the terminal matches a preset time.

[0051] The media synchronization data is sent to each terminal through various transmission channels.

[0052] The following is a detailed description of an embodiment of the above sending method:

[0053] This embodiment implements a cache synchronization service based on a new generation media transmission protocol to ensure reliable and synchronous transmission in heterogeneous networks. The server provides media streams to different devices and different transmission channels. However, due to the differences between these channels, the transmission time of the media streams will vary. Significant differences can severely impact the synchronization effect of multiple terminals. Therefore, the server needs to adjust for different transmission channels, using a cache synchronization algorithm to ensure that the media streams arrive at the terminals at roughly the same time.

[0054] In one embodiment, the aforementioned transmission channel refers to the link through which the terminal device communicates with the server device, including but not limited to 1-way or 2-way communication networks such as DTMB terrestrial broadcast network, IPTV network and 5G / 4G / 3G broadcast network and public Internet.

[0055] In one embodiment, the preset time refers to the time obtained through a cache synchronization algorithm during the adjustment process for different transmission channels.

[0056] In one embodiment, the server refers to a computing device or system for providing computing, storage, application, or data resources, including but not limited to physical servers, virtual servers, and cloud servers.

[0057] In one embodiment, the terminal refers to a hardware device or software system that directly interacts with the user or communicates with a server device, including but not limited to personal computers, smartphones, tablets, smart TVs, Internet of Things devices, and software-based virtual terminals.

[0058] In one embodiment, media refers to audio, video, and three-dimensional media, including but not limited to voice calls, audio streams, video streams, three-dimensional audio streams, three-dimensional video streams, and multimedia content with synchronized audio and video.

[0059] In one embodiment, the media timing information is the CEU timestamp descriptor. It provides the rendering time of the first AU corresponding to the CEU. If the rendering time of the corresponding media data has expired, the descriptor is ignored. Specifically, the rendering time of the first AU of each CEU and the ceu_sequence_number can be determined according to the CEU timestamp descriptor CEU_timestamp_descriptor in Table 1 below.

[0060] Table 1. CEU Timestamp Descriptor Syntax

[0061]

[0062] descriptor_tag: Identifier used to identify the type of descriptor.

[0063] descriptor_length: The length of the identifier in bytes.

[0064] ceu_sequence_number: Represents the sequence number of the CEU corresponding to the descriptor.

[0065] ceu_presentation_time: Specifies the presentation time of the first AU of the specified CEU, expressed in 64-bit NTP timestamp format.

[0066] In another embodiment, each device uses Network Time Protocol (NTP) to synchronize its time. The time is represented by a 64-bit number, where the first 32 bits represent the integer part of the total seconds, and the last 32 bits represent the fractional part of the total seconds. The time represented by the last 32 bits is the value of the corresponding 32 bits multiplied by 1 / 2. 32 Seconds, so the time precision of an NTP timestamp is 1 / 2. 32 Second.

[0067] In one embodiment of the present invention, the above-mentioned cache synchronization algorithm is as follows: Under broadcast network transmission conditions, such as DTMB terrestrial broadcast network, IPTV network and 5G broadcast network, SMT data packets are transmitted using UDP protocol, and the network latency is relatively fixed, generally within 200ms. Under these conditions, cache control is relatively stable. Setting a fixed time delay for sending media packaged data can ensure that the media stream finally arrives at the terminal at basically the same time.

[0068] In one embodiment, the aforementioned cache synchronization algorithm is as follows: When transmitting data over the Internet, TCP or HTTP protocols are generally used, resulting in significant network latency fluctuations. Therefore, it is necessary to evaluate the network status and implement an adaptive cache algorithm. Here, network status refers to the statistical status of most terminals over a certain period. The statistical status refers to the network characteristics and performance indicators derived from summarizing and analyzing network transmission data from multiple terminal devices within a specific time range. Network status includes, but is not limited to: network bandwidth, network latency, packet loss rate, network fluctuations, terminal connection quality, and historical trends.

[0069] In one embodiment, the above-described cache adaptive algorithm includes, but is not limited to, the following key steps:

[0070] Network status assessment, which involves calculating available bandwidth B through real-time bandwidth measurement and historical bandwidth data statistics. estimated :B estimated =α·B current +(1-α)·B historical , where α is a smoothing factor used to balance real-time bandwidth and historical bandwidth;

[0071] The cache size is dynamically adjusted, i.e., a target cache value is defined: C taget When network fluctuations are large or latency is high, increase C. taget To cope with sudden changes. When the network is stable, reduce C. taget To reduce latency;

[0072] Dynamic bitrate selection, which involves choosing a suitable bitrate R based on bandwidth estimates and buffer status. selected :R selected =max{R i |R i ≤B estimated ∧C buffered >R i ·T min In this process, high bitrate is prioritized to ensure image quality; when network conditions are limited, low bitrate is switched to ensure smooth playback.

[0073] Data prefetching and discarding strategies are implemented. Prefetching refers to preloading more data into the cache when network conditions are good, preparing for potential network fluctuations. Discarding refers to discarding low-priority or expired data to free up space when the cache is overloaded or data is lagging.

[0074] Cache and playback coordination involves periodically synchronizing the cache status with the playback progress to ensure that the audio and video tracks are synchronized and to avoid playback interruptions or desynchronization.

[0075] In one embodiment, based on Table 1 described above, a media time indication information is proposed, the media time indication information including at least one of the following signaling structures:

[0076] Signaling structures used to indicate resource identifier types for media resources; and / or

[0077] A signaling structure used to indicate the length of the resource identifier for a media resource; and / or

[0078] Signaling structures used to indicate media resource sequence numbers; and / or

[0079] A signaling structure used to indicate the timing of media resource presentation.

[0080] The present invention also proposes, as follows Figure 2 The method shown is a receiving method for multi-terminal audio and video synchronization in heterogeneous networks, the receiving method comprising:

[0081] Receive media synchronization data, which includes a general encapsulation unit for synchronization and media timing indication information;

[0082] The media synchronization data is parsed to obtain each general encapsulation unit and the corresponding media time indication information;

[0083] Design a cache adjustment algorithm, which refers to using the master clock based on the absolute rendering time to guide the synchronous rendering of each general-purpose packaging unit, ensuring that the final rendering is consistent with the master clock;

[0084] Based on the media time indication information, the data of each general encapsulation unit is adjusted according to the designed cache adjustment algorithm to obtain media cache adjustment data;

[0085] The media cache adjustment data is then rendered and presented.

[0086] In one embodiment of the present invention, the media time indication information is a CEU timestamp descriptor. It provides the presentation time of the first AU corresponding to the CEU. Specifically, the presentation time of the first AU of each CEU can be determined according to the CEU_timestamp_descriptor in Table 1. The media time indication information in this receiving method is the same as the corresponding content in the sending method, and will not be described again here.

[0087] In one embodiment, media time indication information, such as descriptor_tag, descriptor_length, ceu_sequence_number, and ceu_presentation_time, can be used to indicate the type and length of the identifier, the corresponding CEU sequence number, and the presentation time of the first AU of the specified CEU. The presentation time is represented in 64-bit NTP timestamp format.

[0088] In one embodiment, synchronous presentation is guided by the SMT master clock. The SMT clock is a master clock based on the absolute presentation time, obtained by subtracting the presentation timestamp (e.g., ceu_presentation_time) from the media time indication information received by the receiver from the current system time.

[0089] In one embodiment, the receiver buffer adjustment algorithm includes: playback of terminal media is based on the SMT master clock, meaning the playback duration of the media must be consistent with the SMT master clock. If a deviation occurs, an adjustment mechanism is needed to correct it. The adjustment mechanism must consider the user experience, and the specific adjustment mechanism is as follows:

[0090] d represents the difference between the media playback duration and the SMT master clock. When this difference deviates, it needs to be adjusted, as shown in (1):

[0091]

[0092] Here, D is the adjustment threshold. When d is greater than the threshold D, it indicates that the current media playback is significantly ahead of schedule. In this case, frame stopping is used, and the user perceives the media stream as stationary. When d is less than -D, it indicates that the media playback is significantly behind schedule. In this case, frame dropping is used, and the user perceives the media data as suddenly jumping. When the deviation is relatively small (D>d>-D), fine-tuning is used.

[0093] In one embodiment, the specific selection of the above-mentioned frame-stopping method includes, but is not limited to: stopping the currently playing frame, that is, directly freezing the currently playing frame as the stop frame; or stopping the most recent keyframe, that is, locating the most recently decoded keyframe (I-frame) as the stop frame; or stopping the most recent static frame, that is, preferentially selecting the most recently decoded relatively static image (such as a low-motion area or static shot) as the stop frame. By flexibly selecting the stop frame, the system can balance smoothness, image quality, and user experience in different scenarios, providing a more intelligent frame-stopping processing solution.

[0094] In one embodiment, the specific selection of the above-mentioned frame dropping method includes, but is not limited to: dropping frames by frame type priority, that is, discarding B frames first, as they have the least impact on the picture, then discarding P frames, and only considering discarding I frames when absolutely necessary. Alternatively, dropping frames by timeline, that is, discarding frame data that exceeds the playback time window (i.e., delayed frames), prioritizing the retention of frames close to the current playback time to avoid excessively abrupt playback jumps. Alternatively, dropping frames by group, that is, when the cache is overloaded or the network is limited, discarding a group of frames (such as GOP - Group of Pictures) to quickly reduce cache pressure. Alternatively, dropping frames by content importance, that is, analyzing the content in the frames, prioritizing the retention of frames corresponding to important scenes (such as characters, subtitles, etc.), and discarding frames with significant background changes. These frame dropping methods can effectively balance picture quality and playback smoothness under resource constraints, ensuring the optimization of the overall user experience.

[0095] In one embodiment, the above-described fine-tuning method is as shown in (2):

[0096]

[0097] The basic idea of ​​fine-tuning is to speed up or slow down media playback, but the acceleration or deceleration should not be too large. The adjustment range should be between 90% and 110% of the original speed, otherwise it will cause discomfort to the user.

[0098] In another embodiment, the terminal cache adjustment algorithm includes introducing an NTP time synchronization mechanism into the terminal player. Through the NTP time synchronization mechanism, continuous time synchronization with the server ensures that the standard time that the terminal player can reference is within a precise range.

[0099] An embodiment of the present invention, for example Figure 3 The overall flowchart of the proposed method for transmitting and receiving media synchronization across multiple terminals in heterogeneous networks is shown.

[0100] Specifically, during transmission, the SMT server encapsulates the presentation timestamp of each CEU in a timestamp descriptor. The CEU timestamp descriptor provides the presentation time of the first AU for the corresponding CEU, represented in 64-bit NTP timestamp format. Then, the encapsulated data is packaged and cached using a cache synchronization algorithm to obtain the media stream. Finally, the media stream and signaling are sent together to the terminal.

[0101] Specifically, during the reception process, the receiving end receives the CEU and timestamp descriptor via the SMT transmission standard, and parses the CEU_timestamp_descriptor information from it, such as descriptor_tag, descriptor_length, ceu_sequence_number, and ceu_presentation_time. Then, based on the decoded ceu_presentation_time information, the terminal performs buffer adjustment, using a master clock based on the absolute presentation time (i.e., the SMT master clock) to guide the synchronous presentation of various media contents. The SMT master clock is obtained by subtracting the ceu_presentation_time received by the player from the current system time. To ensure that the system time of each presentation terminal is consistent, an NTP server is required to provide unified time synchronization for different terminals. Finally, a buffer adjustment algorithm is used to adjust the pre-decoding video buffer, pre-decoding audio buffer, video image buffer, and audio sampling buffer to ensure that the final presentation is consistent with the master clock.

[0102] The present invention also proposes, as follows Figure 4 The illustrated device is a transmission apparatus for simultaneous audio and video transmission across multiple terminals in a heterogeneous network, corresponding to... Figure 3 The packet streaming server in the middle is used to perform tasks such as... Figure 1 The transmitting method is shown. The transmitting device includes:

[0103] The encapsulation module is used to encapsulate all general-purpose encapsulation units and media timing indication information;

[0104] The packaging module is used to package the media encapsulation data;

[0105] The cache synchronization module is used to cache and synchronize the media packaged data.

[0106] The transmission module sends the obtained media synchronization data to each terminal through various transmission channels.

[0107] The present invention provides a receiving device for multi-terminal media synchronization in heterogeneous networks, corresponding to... Figure 3 The presentation terminal in the middle is used to perform actions such as Figure 1 The receiving method is shown. The receiving device includes:

[0108] The receiving module is used to receive media synchronization data;

[0109] The parsing module is used to parse the media synchronization data to obtain each general encapsulation unit and the corresponding media time indication information;

[0110] The cache adjustment module designs a cache adjustment algorithm to adjust the data of each general encapsulation unit to obtain media cache adjustment data;

[0111] The rendering module renders and presents the media cache adjustment data.

[0112] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for transmitting media synchronously across multiple terminals in a heterogeneous network, characterized in that, The sending method includes: All general encapsulation units and media timing indication information are encapsulated to obtain media encapsulation data, wherein the media timing indication information includes the presentation time corresponding to each general encapsulation unit; The media encapsulation data is packaged to obtain media packaged data; A cache synchronization algorithm is designed to send media packaged data to each terminal through various transmission channels, ensuring reliable and synchronous transmission in heterogeneous networks. The cache synchronization algorithm refers to adjusting different transmission channels to ensure that the media packaged data arrives at the terminal at approximately the same time. The media packaged data is then processed through the cache synchronization algorithm to obtain synchronized media data. The media synchronization data is sent.

2. The method for transmitting media synchronously across multiple terminals in a heterogeneous network according to claim 1, characterized in that, The aforementioned cache synchronization algorithm refers to adjusting the transmission channels to ensure that the media packaged data arrives at the terminal at roughly the same time, thus guaranteeing reliable and synchronous transmission in heterogeneous networks.

3. The method for transmitting media synchronously across multiple terminals in a heterogeneous network according to claim 1, characterized in that, The media time indication information includes at least one of the following signaling structures: Signaling structures used to indicate resource identifier types for media resources; and / or A signaling structure used to indicate the length of the resource identifier for a media resource; and / or Signaling structures used to indicate media resource sequence numbers; and / or A signaling structure used to indicate the timing of media resource presentation.

4. A method for receiving media synchronization across multiple terminals in a heterogeneous network, characterized in that, The receiving method includes: Receive media synchronization data, which includes a general encapsulation unit for synchronization and media timing indication information; The media synchronization data is parsed to obtain each general encapsulation unit and the corresponding media time indication information; Design a cache adjustment algorithm, which refers to using the absolute presentation time as the reference master clock to guide the synchronous presentation of various media contents, adjusting the pre-decoding video cache, pre-decoding audio cache, video image cache and audio sampling cache to ensure that the final presentation is consistent with the master clock; Based on the media time indication information, the data of each general encapsulation unit is adjusted according to the designed cache adjustment algorithm to obtain media cache adjustment data; The media cache adjustment data is presented and rendered on the terminal.

5. The receiving method for multi-terminal media synchronization in heterogeneous networks according to claim 4, characterized in that, The aforementioned cache adjustment algorithm refers to using the absolute presentation time as the base clock to guide the synchronous presentation of various media contents, adjusting the pre-decoding video cache, pre-decoding audio cache, video image cache, and audio sampling cache to ensure that the final presentation is consistent with the master clock.

6. The receiving method for multi-terminal media synchronization in heterogeneous networks according to claim 4, characterized in that, The media time indication information includes at least one of the following signaling structures: Signaling structures used to indicate resource identifier types for media resources; and / or A signaling structure used to indicate the length of the resource identifier for a media resource; and / or Signaling structures used to indicate media resource sequence numbers; and / or A signaling structure used to indicate the timing of media resource presentation.

7. A transmitting device for multi-terminal media synchronization in heterogeneous networks, characterized in that, The transmitting device includes: The encapsulation module is used to encapsulate all general-purpose encapsulation units and media timing indication information; The packaging module is used to package the media encapsulation data; The cache synchronization module is used to cache and synchronize the media packaged data. The transmission module sends the obtained media synchronization data to each terminal through various transmission channels.

8. A receiving device for multi-terminal media synchronization in heterogeneous networks, characterized in that, The receiving device includes: The receiving module is used to receive media synchronization data; The parsing module is used to parse the media synchronization data to obtain each general encapsulation unit and the corresponding media time indication information; The cache adjustment module designs a cache adjustment algorithm to adjust the data of each general encapsulation unit to obtain media cache adjustment data; The rendering module renders and presents the media cache adjustment data.

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